<?php
/**
 * Created by PhpStorm.
 * User: jiaosuxin(Silas@sf-express.com)
 * Date: 2019-07-15
 * Time: 15:58
 */

class PHPExcelHelper
{
    // 生成表头A、B、C...
    public static function base26($num, $start = 65) {
        $str = '';
        if (floor($num / 26) > 0) {
            $str .= self::base26(floor($num / 26) - 1);
        }
        return $str . chr($num % 26 + $start);
    }
}